Filtration of tobacco smoke



Jan. 12, 1960 J. w. KINNAVY FILTRATION OF. TOBACCO SMOKE Filed April 3, 1958 Jzae Jwea %%777 United States Patent rice FILTRATION or TOBACCO SMOKE James W. Kinnavy, Elmhurst, Ill., assignor to Wallace A. Erickson & Co., Chicago, 11L, a corporation of Illinois Application April 3, 1958, Serial No. 726,273 6 Claims. c1; 131-10 This invention relates to the treatment of tobacco smoke for the purpose of reducing the presence of undesired constituents therein and means to accomplish this result.

The harmful physiological effects of volatile constituents contained in tobacco smoke have long been recognized. It is well known, for example, that tobacco smoke contains various alkaloids and health-affecting volatile materials such as nicotine and also tarry and other constituents which tend to physiologically irritate the smoker. Attempts have been made to obviate the harmful effects induced or aggravated by these materials by using filters. However, the various filtering devices and processes of the prior art have not been entirely satisfactory, although in many cases they remove, to some degree, toxic materials. For example, some of the methods and devices used for filtering tobacco smoke fail to satisfy completely the needs of the smoker or tobacco industry because they only remove a small portion of the toxic materials, are inconvenient to use, unfavorably influence the taste of the tobacco smoke, or adversely affect the burning characteristics of the tobacco.

I have found that it is possible, by use of a simple filtering operation and device, to remove substantial quantities of the harmful constituents of tobacco smoke evolved from burning tobacco without altering appreciably the flavor generally associated with tobacco smoking articles. This is accomplished by contacting tobacco smoke with trimethyloctadecylammonium stearate, whereby the nicotine and tars become bound to the stearate. Although the use of trimethyloctadecylammonium stearate itself serves to retain alkaloids such as nicotine and tars present in tobacco smoke, the stearate may be retained by a material which serves as a filter as well as carrier for the stearate. For example, the stearate may be adsorbed on porous materials such as exemplified by cellulosic products (e.g., cellulose acetate, paper, cotton, and wood), asbestos wool, particles of pumice stone, silica gel, cork, glass, wool, earth and plastic materials. These materials may be formed in the shape of cylindrical cartridges or inserts, or packed in cylindrical capsules or envelopes. Whatever form or shape filter is used, it may be retained within smoking articles such as cigarettes, cigars, cigarette or cigar holders, or pipes in a conventional manner, thereby permitting tobacco smoke to be drawn into contact with the filter before entering the mouth of the smoker.

Also, I have found that trimethyloctadecylammonium stearate has a superior capacity to retain tars and alkaloids such as nicotine much more effectively than other stearates such as p-d-iisobutylphenoxyethoxydimethylammonium stearate, sodium stearate, ammonium stearate, triethanolamine stearate, piperazine stearate, and morpholine stearate.

The invention is illustrated in the accompanying drawing which shows a partially broken away perspective view of a cigarette having disposed therein tobacco and a tobacco smoke filter adapted to permit the passage of smoke 2,920,629 Patented Jan. 12, 196Q 2 therethrough. The filter comprises a cylindrical insert of asbestos wool having trimethyloctadecylammonium stearate included therein. The drawing shows the same cigarette wrapper circumscribing the tobacco .and filter insert.

The following example illustrates a satisfactory procedure for distributing trimethyloctadecylammonium stearate on cotton fibers to form a filter.

Example About 1390 parts by weight of about a 25% isopropyl alcohol solution of trimethyloctadecylammonium chlo-, ride may be added to a vessel containing about 2 grams of cotton. About 1224 parts by weight of about a 25 mixture of sodium stearate dispersion containing about 10% water and about 65% isopropyl alcohol should then be added at room temperatures, with agitation, to the vessel. Commercially available, triple-pressed stearic acid may be used in making the sodium stearate.

An immediate reaction occurs whereby the resulting trimethyloctadecylammonium stearate is formed directly on the cotton fibers. This reaction may be shown as follows:

In this process, the trimethyloctadecylammonium chloride is first adsorbed by the cotton, and trimethyloctadecylammonium stearate is afterwards formed directly on the cotton fibers upon the addition of sodium stearate to the vessel.

The deposition of about one gram of trimethyloctadecylammonium stearate on 2 grams of cotton produces an excellent filter, although satisfactory results may be obtained with less than this amount.

The impregnated cotton should be removed from the vessel, dried in a conventional manner and formed into a cylindrical filter for use in a cigarette. The resulting filter will have the water-insoluble trimethyloctadecylammonium stearate afiixed to its fibers. Nicotine and tars become readily bound to the stearate retained by the cotton carrier.

The concentration of the reactants in the above example is not critical because a high proportion of the trimethyloctadecylammonium stearate reaction product formed in the liquid media will be deposited on and/or adsorbed by the carrier irrespective of its concentration in the solution. However, a sufficient amount of stearate reaction product should be formed so as to assure the deposition or formation of an eifective amount of the cationic stearate reaction product on the carrier. As i1- lustrated in the above equation, one mole of trimethyloctadecylammonium chloride and one mole of sodium stearate react to form one mole of trimethyloctadecylammonium stearate.

By using an anionic carrier, the ionic attraction of the cationic stearate reaction product to the anionic carrier will be sufiiciently great so as to tend to assure the deposition of high levels of stearate reaction product on the carrier. Therefore, it is advantageous to add, first, the chloride to the carrier and then add sodium stearate to the vessel so that the resulting reaction product is formed directly on the carrier. 0n the other hand, if desired, trimethyloctadecylammonium stearate may be first formed, then substantially dissolved in hot chloroform, and finally applied as a solution to the carrier.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.

.I claim:

1. A tobacco smoke filter comprising a supporting mass adapted to afford passage of tobacco smoke therethrough, said mass 7 including trimethyloctadecylammonium stearate. -.2. An improved tobacco smoke filter comprising a cylindrical tobacco smoke filter having an efiective amount of trimethyloctadecylammonium stearate as 'a filtering aid.

3. A tobacco smoke filter comprising a supporting mass of material adapted to alford passage of tobacco smoke therethrough, said mass containing trimethyloctadecylammonium stearate.

4. The method of treating tobacco smoke to reduce irritating constituents therein, which comprises contacting the smoke with trimethyloctadecylammonium stearate.

5. The method of treating'tobacco smoke to reduce irritating constituents therein, which comprises contacting the smoke with trimethyloctadecylammonium stearate which is supported by a carrier.

6. A tobacco smoking articlehaving disposed therein tobacco and a tobacco smoke filter adapted to permit the passage of the smoke therethrough, said filter comprising a supporting mass which includes trimethyloctadecylammonium stearate, whereby irritating constituents in tobacco smoke are retained by said filter when smoke from the burning tobacco is drawn through said filter.

References Cited in the file of this patent UNITED STATES PATENTS 2,158,565 Andrews May 16, 1939 

1. A TOBACCO SMOKE FILTER COMPRISING A SUPPORTING MASS ADAPTED TO AFFORD PASSAGE OF TOBACCO SMOKE THERETHROUGH, SAID MASS INCLUDING TRIMETHYLOCTADECYLAMMONIUM STEARATE. 